If you want to keep the original look of the current exposed aluminum, DON'T SAND BLAST THAT PART OF THE WHEEL. Been there, done that, was disappionted. It'll give it a textured finish and the smooth aluminum finish will be gone. It won't be a shiny silver anymore. When recoated in clear, this new textured finish will have a light gray color to it. The only way to get back a bright aluminum finish there will be to sand and buff. When I did mine, I didn't want to get into it that far. The finish under the gold part will be a very mildly textured finish already, so blasting there is OK. But that doesn't solve the problem with the current clear only part of the wheel.
Having learned my lesson once, I found a paint stripper that was safe to use on aluminum and used that to remove the coating. Ask at the dealer, they can refinish a wheel there, and they can strip the coating without damaging the bright aluminum. Perhaps they'll only strip them for a small fee.
Another thing to try might be to get a wheel from the junkyard and experiment on it first before doing your wheels. It may save a set of 4 wheels is you make a mistake.